The food industry produces enormous quantities of by-products such as peels, seeds or stones. In most cases, bioactive substances like carotenoids in carrot peels or polyphenols in coffee grounds can be recovered, adding value to these wastes. Microwave-assisted extraction enables highly efficient recovery with shorter extraction times and lower solvent consumption compared to other processes.
The project aims to develop an integrated process and reactor design for future industrial implementation, where by-products from agro-industrial processes (e.g. carrot peels) can be valorized by recovering high-value non-polar components (e.g. carotenoids, well recognized natural pigments and widely used in the food and cosmetic industries) through a microwave intensified microemulsion extraction process. The AMICREX concept can be extended to address the challenges proposed by extraction of non-polar metabolites, especially carotenoids, from other renewable biomass sources (e.g. Microalgae).
To optimize the microwave-assisted extraction process, knowledge about the dielectric properties of materials is required; however, data on typical by-products of the food industry are scarcely found in the literature. The present study investigates the influence of temperature and moisture content (M) on the dielectric constant (ε′) and loss (ε′′) of carrot waste, apple pomace, pineapple peel and spent coffee grounds at 2.45 GHz.
The resulting data at different temperatures were significantly influenced by the composition of the investigated materials. Although the dielectric properties of fresh food are partly described in the literature, data are not always suitable for estimating the properties of food waste, as processing often leads to changes in composition.
Katalin Solyom, Pilar Rosales López, Patricia Esquivel, Ana Lucía Vásquez-Caicedo: Effect of temperature and moisture contents on dielectric properties at 2.45 GHz of fruit and vegetable processing by-products, RSC Adv., 2020, 10, 16783–16790
Amicrex – Development of a Microwave Assisted Cell Disruption of Biomass and Extraction of Valuable Compounds
May 2015 – January 2020
The research leading to results in this project receives funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement n°661198.
Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB